Internal pipe wrench



INTERNAL PIPE WRENCH Filed Nov. 12, 1958 Oct. 11, 1960 FIG. 2

FIG. 6

FIG. 5

INVENTOR. ALBERT /ZZO BY kfiafasej. golm pg ATTORNEY '---without disengaging the 2,955,497 Patented Oct. 11, 1960 2,955,491 I INTERNAL PIPE WRENCH Albert Izzo, New York, N.Y. (8221 Grand Ave., Elmhurst 73, N.Y.)

Filed Nov. 12, 1958, Ser. No. 773,305

3 Claims. 01. 81 -72) The present invention relates to internal pipe wrenches and more particularly to a cam type adapted to inserting or extracting pieces of pipe in threaded connection.

The invention is particularly utile in applications where it is required to turn the pipe in either direction.

Similar wrenches and devices of the prior art have been employed in the troublesome task of removing broken pieces of threaded pipe, and inserting new pieces in lieu thereof, but these have been relatively fragile i-n construction and subject to frequent breakage. Other types relying upon an externalgrip have damaged the threads 'of the pipe and caused outer disfiguration of the pipe fitting. Still other types cannot readily turn in either direction wrench, thereby rendering them time consuming.

The present invention contemplates the provision of an internal pipe wrench wherein a pair of full length gripping jaws, which are readily replaceable, and which may easily be turned in either direction without disengaging the wrench, provide a positive and firm gripping action to remove or insert a length of threaded pipe, simply, effectively and without damage or disfiguration thereto.

The invention further provides that the gripping jaws of the wrench be readily removable and replaceable, so that in the event of wear, damage, or the like, a defective jaw may be replaced by a new one any number of times, thereby prolonging the life of the wrench.

It is therefore one of the objects of the present invention to provide an internal pipe wrench of the above indicated nature, wherein the foregoing disadvantages are eliminated, and to do so in a novel and eflFective manner.

Another object of the invention is to provide an internal pipe wrench capable of turning in either direction without disengaging the wrench from the pipe being turned.

Still another object of the invention is to provide a wrench of the above indicated nature extremely adaptable for removing pieces of threaded pipe.

Another object of the invention is to provide a novel type of internal pipe wrench adaptable for inserting new pieces of pipe, pipe nipples and the like, that are in threaded connection.

Still another object of the invention is to provide an internal pipe wrench wherein the gripping jaws thereof provide a full length maximum grip against the sides of the pipe to insure a maximum and effective grip thereon.

Another object of the invention is to provide. a pipe wrench wherein the worn gripping jaws thereof may be cheaply and simply replaced to prolong the life of the wrench.

A further object of the invention is to provide a wrench of the above indicated nature which will not damage the threads of the pipe being turned and will not cause outer disfiguration thereof.

Another object of the invention is to provide a wrench of the above type which will be operable either with a Socket wrench, boxocket, or open end wrench.

A further object of the invention is to provide a tool of the above nature which Will be simple and economical to manufacture, yet positive and reliable in operation.

The foregoing and other objects and advantages will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawing, wherein one embodiment of the invention is illustrated by way of example.

It is to be expressly understood however, that the drawing is for the purposesof illustration only, and is not to be construed as defining the limits of the invention.

Referring to the drawing, wherein like reference characters designate like parts;

Figure 1 is an elevation view of the invention.

Figure 2 is an end view of Figure 1.

Figure 3 is a perspective view of one of the replaceable full length gripping jaws of the invention.

Figure 4 is a perspective view showing the invention in engagement with the interior of a pipe.

Figure 5 is a section view taken along the line 5-5 of Figure 4.

Figure 6 is a section view similar to Fig. 5 showing the invention engaged with the intenior of a pipe being turned in the opposite direction from that shown in Figure 5.

Referring now to Figure 1, a wrench assembly generally designated by the numeral 10, comprises a substantially hexagonal part 12, and a cylindrical part 14. A peripheral surface 16, of the cylindrical part 14, comprises a series of serrations 18, running axially for the entire length thereof (Figs. 1 and 2) so as to form a continuous gripping surface.

The cylindrical part further contains a pair of symmetrical cutouts 20 and 22 (Figure 2) which are identical to one another in reverse order. The cutouts 20 and 22 correspond in size, form, and arrangement on opposite sides of the plane of symmetry P-P of the entire wrench assembly 10, each part having its counterpart in reverse order on the opposite side of the plane.

The cutouts 20 and 22 run the entire length of the cylindrical part 14, and in form comprise a circular section 24, which for reasons hereinafter explained is greater than degrees of a circle, to form a throat 26, from which a pair of flat surfaces 28 and 30 flare outward to the peripheral surface 16.

Referring now to Figure 3, a solid cam gripping jaw 32, adaptable to be axially inserted in the cutouts 20 and 22 comprises a cylindrical portion 34, the continuity of surface of which is interrupted by a pair of outwardly flaring flat surfaces 36 and 38 extending to a circular peripheral surface 40. The peripheral surface 40 is longitudinally serrated in the same manner as the surface 16.

The cam gripping jaw 32 is so constructed to fit snugly, but turnably within the cutouts 20 and 22, and may freely turn therein within the limits permitted by the flat surfaces 28 and 30 of the cutouts 20 and 22.

The circular portion 24, of the cutouts 20 and 22 being greater than 180 degrees, as hereinbefore stated, it will be readily apparent that the cam gripping jaw 32, may only be inserted therein, or removed therefrom axially, the throat 26 being too narrow to permit the cylindric-al portion of the cam jaw to pass therethrough. For that reason, a shoulder 42 is provided, correspondingly slotted so as to permit passage of the gripping jaws 20 and 22 (Figures 1 and 2), and there is further provided a groove therein adapted to receive a lockring 44. The latter is of the split type and installed in the prescribed manner, so that the cam gripping jaws are locked firmly in place.

It is now apparent that either gripping jaw may be readily replaced by the simple operation of removing the lockring 44.

Referring now to Figure 4, wherein the wrench assurface 36 of the cam gripping jaw 32 is resting against; the flat surface 30, then the peripheral part 40 thereof is entirely contained within the diameter D of the cylindricl part of the wrench assembly, whereas when surface 38 of the cam gripping jaw 32 is bearing against the fiat surface 28, then the peripheral surface 40, protrudes outside of the diameter D.

Having thus described the invention, it will now be apparent to those skilled in the art, that when the wrench assembly 10, is inserted inside the diameter of a pipe and turned as in Figure in a direction A, one of the cam gripping jaws will be brought to bear against the surface 28 while its counterpart will be forced towards the surface 30. The jaw bearing against the surface 28 will therefore protrude beyond the diameter D to firmly and positively engage the pipe 46. Simultaneously a wedging action will result whereby a good part of the peripheral surface 16 will also be forced into engagement with the inside of the pipe, and the longitudinal serrations 18 on the cylindrical portion 14 and on the cam jaw itself will provide a firm and positive grip on the pipe along the entire inserted length of the wrench. At this point, the opposite gripping jaw bearing against the surface 30 is entirely contained within the diameter D, and unable to interfere with the turning motion.

When the direction of turn is reversed towards the direction B as in Figure 6, and it will now be readily apparent that this may be accomplished without disengaging the wrench from the pipe, then the heretofore protruding gripping jaw, necessarily due to the turning action, will be rotated within its cutout, and brought to bear against the surface 30, and thereby rotate to a position inside the diameter D. The counterpart gripping jaw however, due to the same turning motion will be brought to bear against the surface 28 and assume a position protruding outside of the diameter D, so that it will now be operative to firmly engage the interior of the pipe and to wedge the wrench against the side thereof so that the serrations will firmly and positively grip and turn the pipe.

The foregoing procedure may be repeated at will, thereby turning the pipe in either direction required without disengaging the wrench. Because the cam gripping jaws 32 extend for the entire length of the cylindrical portion 14, and because the latter is completely serrated about its entire surface, a stronger and more positive grip is attained on the interior of the pipe than heretofore possible with current tools of this type. In addition, the general robustness of such an arrangement renders this wrench less susceptible to breakage.

It will thus be seen that there is provided a novel wrench for use in removing broken pieces of pipe, and similar applications, in which the several objects of this invention are achieved, and which is well adapted to meet the conditions of practical use.

Although only one embodiment of the invention has been illustrated and described, other changes in the form, and modifications in the relative arrangement of parts, which will be apparent to those skilled in the art may be made without departing from the spirit and scope of the invention.

What is claimed is:

1. An internal pipe wrenchior turning a pipe in either direction without disengaging'the wrench from the pipe comprising, a hexagonal section adapted to cooperate with a turning means and a cylindrical section axially aligned therewith, a serie of serrations on the periphery of said cylindrical section for engaging the interior of said pipe, a longitudinal slot axially extending the entire length of said cylindrical section, a serrated cam gripping jaw for. engaging the pipe turnably disposed within saidslot, said cam jaw having a greater distance from its axisof rotation to its serrated periphery than from said axi to theserrated periphery of said cylindrical section, a second longitudinal slot symmetrical to said first slot in reverse order on the opposite side of a plane of symmetry extending longitudinally through said wrench in said cylindrical section, and an identical cam jaw turnably disposed in the second slot whereby upon turning the wrench in one direction or the other one jaw will protruderadially outside said cylindrical section to grip said pipe and the other jaw will remain contained within said cylindrical section.

2. An internalpipe wrench adapted to be inserted into a section of pipe to turn the pipe in either direction comprising, a serrated cylindrical section and a hexagonal section, a pair of cutouts extending the entire length of the serrated section identical to one another in reverse order on the opposite sides of a plane of symmetry extending longitudinally through said wrench, a cam-like serrated gripping jaw turnably disposed in one of said. slots, said cam jaw having a greater distance from its axis of rotation to its serrated periphery than from said axis to the serrated periphery of said cylindrical section and being adapted to turn the pipe in one direction, an identical gripping jaw turnably disposed in the other of said slots similarly adapted to turn said pipe in the opposite direction, and means for axially securing said gripping jaws in the cylindrical section.

3. In an internal pipe wrench for turning a pipe in either direction without disengaging the wrench from;

the pipe the combination comprising, a serrated cylindrical section, a pair of symmetrical cutouts disposed in reverse order about a plane through the axial center line of said cylindrical section, a serrated cam jaw for gripping the pipe turnably disposed in each of said cutouts conforming to the contour thereof, said cam jaw having a greater distance from its axis of rotation to its serrated periphery than from said axis to the serrated periphery of said cylindrical section, an outwardly flaring surface in each of said cutouts associated with said cam jaws, one of said surfaces operating to limit the movement of its associated cam jaw as the jaw moves beyond the periphery of said cylindrical section to grip said pipe upon turning said wrench in one direction, and the other surface operating to limit the movement of its associated cam jaw as the jaw moves beyond the periphery of said cylindrical section to grip said pipe upon turning the wrench in the opposite direction.

References Cited in the file of this patent UNITED STATES PATENTS 

